Forward function declarations in a Bash or a Shell script?

Question

Is there such a thing in bash or at least something similar (work-around) like forward declarations, well known in C / C++, for instance?

Or there is so such thing because for example it is always executed in one pass (line after line)?

If there are no forward declarations, what should I do to make my script easier to read. It is rather long and these function definitions at the beginning, mixed with global variables, make my script look ugly and hard to read / understand)? I am asking to learn some well-known / best practices for such cases.

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For example:

# something like forward declaration function func  # execution of the function func  # definition of func function func {     echo 123 } 

Answer 1

Great question. I use a pattern like this for most of my scripts:

#!/bin/bash  main() {     foo     bar     baz }  foo() { }  bar() { }  baz() { }  main "$@" 

You can read the code from top to bottom, but it doesn't actually start executing until the last line. By passing "$@" to main() you can access the command-line arguments $1, $2, et al just as you normally would.

Answer 2

When my bash scripts grow too much, I use an include mechanism:

File allMyFunctions:

foo() { }  bar() { }  baz() { } 

File main:

#!/bin/bash  . allMyfunctions  foo bar baz